A hybrid vehicle may include an engine and an electric motor as propulsion sources. The engine may be stopped from time to time to conserve fuel. For example, if the vehicle is traveling downhill or if driver demand torque is less than a threshold torque, the engine may be stopped to conserve fuel. The engine may be restarted to provide torque if driver demand increases or if battery state of charge is reduced to less than a threshold amount of charge. However, because driving conditions may vary, it may be possible to restart the engine and then stop the engine after a few seconds because driving conditions change. Starting the engine for only a few second and then stopping the engine may degrade fuel economy, increase starting component degradation, and aggravate vehicle occupants. Further, there may be little if any benefit realized for starting the engine. Therefore, it may be desirable to provide a way of improving the engine starting decision process so that engine starting may be avoided if engine starting will provide little benefit, while also allowing engine starting if engine starting is expected to provide useful benefit.
The inventors herein have recognized the above-mentioned issues and have developed a powertrain operating method, comprising: receiving data to a controller; adjusting a state of a first engine start request generated via a first control agent responsive to the data; adjusting a state of a second engine start request generated via a second control agent responsive to predicted vehicle conditions; and starting or not starting an engine responsive to arbitration of the first engine start request and the second engine start request.
By providing two control agents that generate different engine starting requests responsive to present vehicle operating conditions and predicted vehicle operating conditions, it may be possible to provide the technical result of improved engine starting decision making. The engine may not be started or it may be started via the improved decision making process. The engine starting decisions may be made responsive to battery state of charge, propulsion motor torque, driver demand torque, and other conditions. The conditions may be evaluated by first and second control agents and then the control agents may request an engine start. An arbitration logic section makes a final determination as to whether or not an engine start request is issued and the engine is started.
The present description may provide several advantages. For example, the approach may reduce a number of times an engine is started and run for a short period of time. Further, the approach may reduce engine starting component degradation. In addition, the approach may be applied to different conditions that may be the basis for engine starting.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.